The present invention concerns an oscillating winding weight for a timepiece with an automatic movement. More particularly, the invention concerns a winding weight of this type intended to be fitted to a wristwatch including a transparent back cover, said weight being arranged on the side of the back cover of the case and allowing permanent observation of the whole of the movement.
Wristwatches having cases with transparent back covers to allow observation of their movement are already known. However, when these watches include a movement with automatic winding mechanism, observation of the movement is always curtailed by the presence of the oscillating winding weight which, even when pierced, as is the case in so-called  less than  less than skeleton greater than  greater than  watches, prevents comfortable observation of the movement.
The main object of the present invention is thus to overcome the drawbacks of the aforementioned prior art, by providing an oscillating winding weight allowing observation of the movement to which it is fitted without any visible obstacle.
The invention thus concerns an oscillating winding weight for a timepiece including a heavy portion fixed to a connecting element connecting said heavy portion to an arbour fixed to a movement, said weight being intended to be rotatably mounted on said arbour, characterised in that said connecting element is made of a transparent or translucent material.
As a result of this new winding weight structure, it is possible to make the whole of the movement of the timepiece to which it is fitted permanently visible, which gives the timepiece an improved aesthetic appearance.
According to a preferred embodiment of the invention, the connecting element is formed of a full sapphire disc.
It will be noted in particular in this respect that the use of sapphire in a winding weight as a connecting element between the heavy portion and the movement goes against the preconceived ideas of those skilled in the art who, when having to design winding weights, always tend to use materials having a high strength, i.e. a good capacity to absorb the shocks to which the weight is subjected during its rotation.
According to another aspect, the invention also concerns a timepiece including a case formed of a middle part closed by a crystal and an at least partially transparent back cover and in which clockwork movement with an automatic winding mechanism is housed, characterised in that said movement is fitted with an oscillating winding weight as defined hereinbefore.